Zenith srv1300s tv vcr dead

[Mike]

I try to power it on, the tv will cycle for a sec and shut off.

I checked the HOT, and it tests fine.

I also read that there are two to-220 regulators that typically go bad on
these, I went ahead and replaced the 7805, and the 7806 regulators, and the
set still cycles.

I pulled the power supply back out and checked the diodes and voltages. The
secondary supply diodes test fine.

I checked the volteges on the power supply, the 113vdc test post tests a
normal voltage, and I checked the voltages at the regulators and they both
appear to be normal.

There is about 7volts on the 5vdc regulator with a 4.8 to 5v output

there is 11.5 vdc on the 6vdc regulator with about 5.8 to 6vdc output.

The volts are normal. When i try to power it up, it will cycle too quickly
for the HV to come up.

If i disconnect the TV deflection board completely from the circuit, it
still cycles.

Im stuck.

Any Ideas?

 

[Mike]

I failed to mention that the cycle sound is not the standard tick tick, its
just a quick power on and power off within a millisecond.

 

[Shoreline Electronics]

Remove the HOT and try......if it still shuts down , your Hv section should
be OK

Check R607 10 Meg


--
==========================
Jeff Stielau
Shoreline Electronics Repair
344 East Main Street
Clinton,CT 06413
860-399-1861
860-664-3535 (fax)
[email protected]
========================
"If you push something hard enough it will fall over."
Fudd's First Law of Opposition - Sir Sidney Fudd

 

[Mike]

ok. You might be right.

Here is where it gets funny.

I said what the heck. I tried to put a tape in, and it almost took it. the
motor wirred for a sec and then wirred back out. I manually fed the tape
into the unit. I plugged it in, and I hit the power button, it powered on,
and threaded the tape out, and ejected it. Powered back off and wont power
back on. The TV never came on at all.

Does the deflection/HV board require a power on signal from the VCR board?
if not the hv board is got bad components, if so, then the VCR board is bad.

Any ideas? I checked the HOT its fine. I didnt check r607 yet.

 

[Mike]

R607 Brn-Blk-Grn (1meg?) reads 2 megohms on DMM.

 

[Mike]

oops. It is a brown black blue, which is 10 megohms.

its only reading as 2.

Is this the problem?

 

[Mike]

changed it anyway (10meg) and it does the same thing.

it wont let the tape go in. You can hear the motor come on, and then it will
switch direction to spit the tape back out.

if you push the tape in, and hold it half way, you can hear the power supply
cycling (tick tick) through the speaker.

the monitor never ever comes on no mater what you do.

Maybe there is something wrong with the TV and causes the CPU to shut off.

the HOT tests fine, in circuit and out of circuit.

 

[Shoreline Electronics]

2 meg out of circuit?

--
==========================
Jeff Stielau
Shoreline Electronics Repair
344 East Main Street
Clinton,CT 06413
860-399-1861
860-664-3535 (fax)
[email protected]
========================
"If you push something hard enough it will fall over."
Fudd's First Law of Opposition - Sir Sidney Fudd

 

[Mike]

yep.

I replaced it anyway. It still doesnt work.

 

[Mike]

for some reason, the 6v regulator is holding steady around a mere 4.8V

hmm, anyway, if you press power at the same time you put the tape in, The
motor will kick on, and start taking the tape, but it wont thread up to the
heads and play. It just shuts right back off. Neither of the LEDs on the
front ever come on either.

Im leaning more and more to the CPU board.

Any ideas?

 

[Chuck]

for some reason, the 6v regulator is holding steady around a mere 4.8V

hmm, anyway, if you press power at the same time you put the tape in, The
motor will kick on, and start taking the tape, but it wont thread up to the
heads and play. It just shuts right back off. Neither of the LEDs on the
front ever come on either.

Im leaning more and more to the CPU board.

Any ideas?

The 6 volt regulators are notorious for going bad. Chuck